This invention relates to nibbling tools and more specifically to a nibbling tool incorporating a unique die head structure that enables hand direction of the cutting path afforded thereby as opposed to a path determined solely by the directional path of the overall tool including the rotary drill.
Nibbling tools have been available in various forms for many years and include those set forth in UK Patent No. 1,485,795 published Sep. 14, 1977; U.S. Pat. No. 4,489,492 issued Dec. 25, 1984; U.S. Pat. No. 4,748,744 issued Jun. 7, 1988 and U.S. Pat. No. 4,158,913 issued Jun. 26, 1979.
All of the above-noted patents disclose a nibbler tool that includes a single die cutting head and a punch or blade that reciprocates with respect to the die. A source of rotary motion such as a rotary drill is attached to a shaft extending from the rear of the nibbler tool and connected thereto. A handle extends outwardly from the body of the tool in order for the operator to manipulate the tool by grasping both the handle as well as the drill body. In some advanced nibbler tools, a second die head is provided. In such double-ended tools depending upon which die head is utilized for cutting operation at any one time, the other die head is provided with a removable grip or handle that fits firmly over the outside surfaces thereof.
The die head has an entry area or slot for receipt of sheet material such as a thin sheet metal and is provided with a cutting surface that cooperates with the punch or blade. During operation, the punch or blade reciprocates in a linear motion and cooperates with the die cutting surface to bite or nibble a small crescent-shaped piece of material from the sheet with each punch stroke. As the operator's hands guide the tool, the nibbler tool cuts a slot in the direction of motion, that is, the movement of the tool including the drill determines the cutting path. Obviously if it is desired to cut angular or curved slots especially in small spaces, it is extremely difficult to manipulate the tool in the desired cutting path; and, accordingly, this is a drawback of such tools.
Accordingly, it would be highly desirable to be able to provide nibbler tools of the above type with a mechanism that would enable them to be more easily utilized in tight quarters and provide for the movement of the cutting die head independent of the remainder of the tool and the power drill attached thereto. Accordingly, it is the object of the present invention to provide a cutting tool structure having a cutting die head that can be rotated independently of the tool body via one's fingers by providing forward and/or angular motion to the tool by grasping the drill in the other hand. These and other objects of the present invention are accomplished by mounting the die head on the body of the nibbler tool such that it is restrained from axial movement therewith but is free to rotate as determined by the manipulation of the worker's hand in maneuvering the direction of the cutting path. Such independent die cutting head movement enables angular and/or circular cutting paths to be achieved without the attendant movement of the nibbler tool body and attached drill in the same angular and/or circular movement. In this way, angular and/or circular cutting paths can be achieved while utilizing the nibbler tool in restricted areas where similar movement of the tool and attached drill cannot be accomplished due to potential contact with other structures in the work area.
Other objects, features and advantages of the invention shall become apparent as the description thereof proceeds when considered in connection with the accompanying illustrative drawings.